In “12 Strong,” Chris Hemsworth shifts from playing the hammer-wielding warrior Thor to Capt. Mitch Nelson, a character based on Green Beret Mark Nutsch — leader of a 12-man U.S. Special Forces team deployed to Afghanistan after the 9/11 terrorist attacks.

The image is rousingly iconic, if a little incongruous. But it’s a true one, and it’s at the core of “12 Strong,” a movie about the first U.S. special forces that went into Afghanistan weeks after the Sept. 11, 2001, terrorist attacks.

“Honestly, the aesthetics of this story is something we haven’t seen before,” says Chris Hemsworth, the Australian “Thor” actor who plays the movie’s fictionalized Mitch Nelson. The role is based on the real Army Capt. Mark Nutsch, who led 11 colleagues into combat against the Taliban alongside the forces of an uncertain local ally, Northern Alliance warlord Abdul Rashid Dostum (“Homeland’s” Navid Negahban).

“That was one of the things that attracted me to the story: the mashup of the old and new,” Hemsworth continues. “The collaboration of the American soldiers with the local Afghan people, that was another big reason for me.”

The movie recounts how the 12 Americans and Dostum’s forces pinned down vastly more numerous and better-equipped Taliban troops in a precarious mountain pass leading to the strategic north Afghanistan city of Mazar-i-Sharif. Horses and mules were the only way for the allies to access the commanding heights.

So, while the Hollywood cast, which included the likes of Michael Shannon, Michael Pena, Trevante Rhodes and several real military veterans, not only went through the usual war movie boot-camp training, most of the actors had to learn horseback riding for the first time.

“A number of the guys fell off,” says the movie’s producer, Jerry Bruckheimer, whose military-themed projects include “Top Gun,” “Crimson Tide” and “Black Hawk Down.” “Some of the horses spooked when we had explosions. But they were pretty well-trained and our wranglers worked very hard with the actors to get them very proficient at riding. Chris was a good rider when he came in, and some of the others had ridden before, but they all spent a good deal of time working on their riding.”

Although Hemsworth’s wife, Elsa Pataky, is an equestrienne and horse owner (and who also plays Nelson’s wife in the movie), “12 Strong” required saddle skills her husband could not have imagined, let alone mastered in advance. Like maneuvering along high, narrow ledges at the film’s remote New Mexico locations while wearing 40-pound backpacks and brandishing powerful M4 assault rifles.

“I had a lot more experience than some of the guys, but when you got on the horse and you’ve got all that armor, all your gear and the weapons and so on and you’re trying to work out how to shoot, it was kind of like starting from scratch anyway,” Hemsworth says.

“The character I was playing knew how to ride in reality, but a lot of the other actors and their characters had never been on a horse before. So I think it fit the sort of insanity of the whole thing. Everyone was uncertain, off-guard and learning as they go. We had to sort of invent our style of how you hold a weapon on a horse and shoot. It was a lot of fun!”

Some of that style was learned from the many Afghans on the set, actors as well as members of New Mexico’s Afghan community who worked as extras, some of whom had ridden or aided American forces back home.

“Some of the Afghan people and guys who were in Afghanistan during this mission said they used to hold the reins in their teeth, literally like some old classic Western thing,” Hemsworth says. “Some of them would literally pull up the horse, get off and shoot, or shoot from the horse.
“I asked some of the military advisers, ‘OK, what’s the most accurate way of doing it?’ and they just laughed. They’d say, ‘Look, there is no real training for this, specifically. Work out what works for you.’ ”

Reel vs. real

Of course, “12 Strong” is more than a story of Green Berets playing cowboys. It’s about the first on-the-ground fight Americans participated in after Afghanistan’s ruling fundamentalists refused to turn over Osama bin Laden and other al-Qaida leaders they’d been harboring following the 9/11 attacks. The 12 went in relatively blind and, against ridiculous odds, completed their mission. All came back alive.

“They all knew they had $100,000 bounties on their heads if they got turned in to the Taliban,” Bruckheimer says. “They were meeting up with a warlord who they knew nothing about. They had no accurate maps of Afghanistan. They didn’t have enough batteries for their radios; they had to go to Walmart and buy batteries before they left!”

“It was a reminder of how thankful we should be for what these guys do,” Hemsworth adds. “As actors, we love to imagine that we can do heroic things, but we just pretend to do them. These guys actually do heroic things, so it’s pretty inspiring.”

While Hemsworth was recently seen quite successfully playing a funnier, more accessible Thunder God in “Ragnarok” and spent virtually all of last year, as Thor, making two upcoming “Avengers” sequels, he points out that portraying a real-life character like Nutsch/Nelson comes with a different set of considerations.

“You have this wealth of knowledge at your fingertips that you don’t when you’re inventing a character, so to speak,” Hemsworth says. “With a fictional character, you start to think, maybe I can do this or maybe I can do that; sometimes you’re second-guessing the character in a way. Whereas with this, there’s an honest truth portrayal of it, and you know the guy and have a bond with him to sort of hold strong with. That responsibility … on one hand, there’s a pressure, but it’s also a huge advantage.”

Unsung heroes

While “12 Strong” ends on a triumphal note, Bruckheimer acknowledges that, more than 17 years later, the situation in Afghanistan is still going sideways. But he hopes his movie, which was adapted from Doug Stanton’s nonfiction book and directed by Danish documentarian and commercials-maker Nicolai Fuglsig, at least pays overdue tribute to another group of heroes who weren’t born in the USA.

“You want to give the Afghans the integrity and honesty that these troops really portrayed,” the producer says. “There were stories in the book where these farmers came to fight for Dostum; some of them had no shoes, some of them wore dress shoes, some of them were in suits. They just wanted to fight for what they believed in, and against what these poor people have to deal with when the Taliban or al-Qaida or ISIS comes in.

“Some of these refugees that worked on the movie, some of them fought for us. One of them was an adviser to the Marines over there, and he said, ‘Look, this is going to be a very important movie for the Muslim people. It shows that we don’t want these invaders in our country and that we can work with other people. It puts us in a much better light.’ ”

Bob Strauss has been covering film at the L.A. Daily News since 1989. He wouldn't say the movies have gotten worse in that time, but they do keep getting harder to love. Fortunately, he still loves them.